Flat spring of a hold-down assembly for the brake pads of a disc brake

Abstract

Leaf spring (9) of a retainer assembly for the brake pads of a vehicle disc brake, with two main sides and successively a first spring end (9a), a spring middle section (9b) and a second spring end (9c). The spring ends (9a, 9c) are each terminated by positive locking elements (10a, 10c) which extend in opposite directions from the main sides (9.1, 9.2) such that the first positive locking element (10a) is located on the first main side and the second positive locking element (10c) is located on the second main side. The leaf spring has at least two bends (9f, 9e) of opposite bending direction on the spring middle section (9b), of which the bend outer side of the bend (9f) located closest to the first spring end (9a) is on the second main side, and the bend outer side of the at least one further bend (9e) is on the first main side.

Description

[0001] The invention relates to a leaf spring of a retainer arrangement for the brake pads of a vehicle disc brake, with two main sides and successively a first spring end, a spring middle section and a second spring end.

[0002] Such a leaf spring is known from EP 1 898 115 B1. To fasten and secure the brake pads arranged in a pad recess of the disc brake caliper, a two-part retainer assembly extends over the pad recess and simultaneously transversely over the brake pads arranged in the pad recess. A rigid retainer of the retainer assembly is supported against the brake pads towards the disc brake axis. This support is provided by spring force, for which a leaf spring extends along the outside of the retainer, its ends fixed against the brake caliper. This spring exerts a holding force on the retainer towards the disc brake axis, thereby holding the brake pads in their respective receptacles in the brake caliper or in a brake carrier.The retainer and the leaf spring are each of such a length that one end extends into a slot-shaped recess in the brake caliper. The circumferential contour of the slot is adapted to the common cross-sectional contour of the retainer and leaf spring, thus fixing the retainer both radially with respect to the disc brake axis and transversely to it, i.e., in the circumferential direction of the brake disc. However, due to this close adaptation to the common cross-sectional contour of the retainer and leaf spring, the slot in the brake caliper is not easy to manufacture; rather, its production requires special milling tools.

[0003] The invention is therefore based on the objective of making the fastening of the elements of the hold-down arrangement, which includes the leaf spring, easier in terms of assembly and manufacturing technology, without weakening the fastening.

[0004] Regarding the leaf spring, it is proposed that the ends of the spring be terminated by positive-locking elements that extend in opposite directions from the main sides of the leaf spring, such that the first positive-locking element is located on the first main side, and the second positive-locking element is located on the second main side. Furthermore, the leaf spring has at least two bends or kinks with opposite bending directions in its central section. The outer edge of the bend closest to the first spring end is located on the second main side, and the outer edge of the bend of at least one other bend is located on the first main side of the leaf spring.

[0005] The first of these bends is designed to favorably adapt the longitudinal path of the leaf spring to the shape of the slot and, in particular, to the sloping course of the slot's upper inner surface. The other bend, however, is designed to brace itself against the outside of the retainer and thus exert a spring force on it in the direction of the brake linings.

[0006] According to one embodiment of the leaf spring, the first bend, i.e., the bend closest to the first spring end, is located on the first sixth of the leaf spring's total length. Preferably, this first bend is positioned at a distance of 1.5 cm to 3 cm from the first positive locking element.

[0007] The second bend, however, which in the assembled state is intended for support on the outside of the hold-down device, is preferably arranged on the middle third of the total length of the leaf spring.

[0008] According to a further embodiment of the leaf spring, the width of the two main sides of the leaf spring remains constant over the entire length of the leaf spring.

[0009] From an assembly standpoint, it is advantageous that the retainer can be moved into the slot of the brake caliper at an angle. This results in a particularly space-saving solution that nevertheless provides a stable fixation of the retainer. A space-saving solution is especially beneficial for vehicle disc brakes because there is only a small radial clearance on the outside of the brake caliper compared to the vehicle wheel or rim rotating around the caliper. Particularly in the area of ​​the brake pad recess, there is very limited space available for a stable mounting of the retainer or the assembly consisting of the retainer and leaf spring.

[0010] By arranging the slot in the brake caliper, which accommodates the ends of the retainer and leaf spring, at an angle to the axis of rotation of the brake disc, this end of the retainer assembly can be fixed to the brake caliper with little space required, but still stably.

[0011] It is particularly advantageous if the angle at which the slot is arranged with respect to the axis of rotation of the brake disc is between 10° and 35°, and preferably between 15° and 25°. Accordingly, one embodiment of the retainer provides that its first end section is angled relative to the central section at an angle of 10° to 35°, preferably 15° to 25°. An angle of approximately 20° is particularly advantageous. It is therefore advantageous if the slot has the same inclination relative to the central section as the first end section of the retainer. This means that both the first end section of the retainer and the slot are inclined at the same angle with respect to the brake disc axis. This is easy to implement in manufacturing.

[0012] Preferably, the slot is open in the lateral direction of the retainer. The slot is therefore only bounded by a rear wall, an upper inner surface facing the axis of rotation of the brake disc, and a lower inner surface.

[0013] The slot's simple, laterally open design allows for easy manufacturing, for example, directly through casting or by simple machining of the brake caliper with a milling tool. The upper inner surface, the lower inner surface, and the back wall of the slot can be easily shaped and machined. This machining can be performed in a single pass using a disc milling cutter, which is inserted into the brake caliper at an angle, following the depth of the slot. This gives the back wall of the slot a circular arc shape.

[0014] Additionally, it is possible to move the disc cutter slightly laterally after it has been inserted to its maximum depth in the direction of the slot and only then withdraw it. In this manufacturing process, the back wall of the slot consists of a straight central section and seamlessly connected circular arc sections whose centers are located outside the brake caliper and preferably above the pad recess.

[0015] It is advantageous if the recess arranged on the first end section of the hold-down device is open towards the rear wall of the slot as well as towards its upper and lower inner surfaces and is limited on both sides in a lateral direction by side sections of the hold-down device.

[0016] Preferably, this recess has a U-shaped contour. In the assembled state, the front opening of the U-shaped recess faces the rear wall of the slot on the saddle side. The leaf spring engages with one end in the recess, preferably across its entire width.

[0017] It is particularly advantageous that the leaf spring is supported elastically at least on the upper inner surface of the slot and on the outer side of the central section of the retainer. This ensures, on the one hand, that the retainer is attached vertically to the brake disc axis relative to the brake pads or brake linings, and on the other hand relative to the brake caliper. Such a simple attachment significantly reduces the manufacturing effort for the aforementioned components.

[0018] Regarding the hold-down device and its stability, it is advantageous if, at least in its central section, it is designed as a groove consisting of an elongated base and side flanks arranged along the sides of the base. The two side flanks can be further extended by being arranged not only along the base but also along the first end section.

[0019] With regard to the brake caliper, it is proposed that at least the upper inner surface of the slot formed in the brake caliper be arranged at an angle to the axis of rotation of the brake disc. This angle is preferably between 10° and 35°, and particularly preferably between 15° and 25°.

[0020] To prevent weakening of the brake caliper in the area of ​​the retainer mounting, a particularly advantageous design of the brake caliper provides that the material thickness of the brake caliper between the upper inner surface of the slot and the outer surface of the brake caliper increases from the pad recess. Preferably, the material thickness increases in the form of a widening wedge.

[0021] In order to enable the slot to be manufactured using a standard disc cutter, the lower inner surface of the slot is preferably also arranged at an angle to the axis, with the lower inner surface preferably being arranged parallel to the upper inner surface.

[0022] By using a rotating disc cutter, the back wall of the slot is designed such that it extends along a circular arc whose center point is located outside the brake caliper and preferably above the pad recess. Additionally, it is possible to move the disc cutter slightly laterally after it has been inserted to its maximum depth along the slot and only then withdrawn. In this manufacturing process, the back wall of the slot consists of a straight central section and seamlessly connected circular arc segments whose centers are located outside the brake caliper and preferably above the pad recess.

[0023] Regarding the hold-down device, it is proposed that the first end section of the hold-down device be angled relative to the middle section.

[0024] Preferably, the first end section of the hold-down device is provided with a recess for the engagement of the leaf spring.

[0025] Together with the other components of the disc brake, this allows for simplified mounting of the retainer relative to the brake caliper and the brake pads or linings. This is particularly helpful if the first end section is angled relative to the middle section at an angle of 10° to 35°, preferably 15° to 25°.

[0026] The recess in the area of ​​the first end section of the hold-down device is preferably U-shaped and is bounded laterally on both sides by side sections of the hold-down device. These side sections are not separate component parts. Rather, the recess is integrated into a pre-formed hold-down device, for example, by punching or milling. Alternatively, the recess can be formed directly during the manufacture of the hold-down device. The recess opens upwards, downwards, and towards the end of the hold-down device.

[0027] Preferably, the hold-down device is designed, at least on its central section, as a groove consisting of an elongated base and side flanks arranged on the sides of the base. These, among other things, reinforce the hold-down device.

[0028] The width of the groove is preferably equal to the width of the recess at the end section of the hold-down device.

[0029] Regarding the retainer and its stability, it can be advantageous if the two side flanks are extended not only along the base but also along the first end section. These additional side flank sections can serve to provide additional lateral support for the retainer seated in the caliper slot.

[0030] Furthermore, it is advantageous that the end of the first end section is formed by a front face extending along a circular arc whose center point is located outside the hold-down device and preferably above the middle section.

[0031] Specific designs of a disc brake, a brake caliper, a brake retainer, and a leaf spring are explained in more detail below with reference to the drawings. These show: Fig. 1 a perspective view of the brake caliper of a vehicle disc brake including the pad recess formed in the brake caliper with a brake pad arranged therein, as well as a retaining device above the pad recess; Fig. 2 an enlarged view of the object according to Fig. 1 , however, without the parts of the in Fig. 1 Completely reproduced hold-down arrangement; Fig. 3 the objects according to Fig. 1 in a longitudinal section through the brake caliper; Fig. 3a one of the Fig. 3 corresponding longitudinal section, but exclusively through the brake caliper itself and with an additional illustration of a disc cutter positioned in machining position in front of the brake caliper; Fig. 4 the left area of ​​the Fig. 3 on a larger scale; Fig. 5, left area of ​​the Fig. 1 on a larger scale; Fig. 5b the same area as Fig. 5a , however, with no brake pad; Fig. 6 a perspective view of only the brake pad with the backing plate facing the viewer; Fig. 7 in a perspective view only the retainer of the retaining assembly used on the brake caliper; Fig. 8 in a perspective view only the leaf spring used on the brake caliper as part of the retaining assembly; Fig. 9 in a perspective view only the leaf spring and the retainer as the essential components of the retaining assembly; Fig. 10 in a perspective view only the bracket used on the brake caliper, which serves simultaneously as a support element and as a locking element; Fig. 11 in a perspective view a second embodiment of the retainer, and Fig. 12 the retainer according to Fig. 11 in a longitudinal section.

[0032] The Figuren 1 - 3a show the central part of brake caliper 1 of a vehicle disc brake for commercial vehicles. Figur 2 shows the brake caliper in an enlarged view, Figur 3 und Fig. 3a in a longitudinal section. The disc brake can be of the sliding caliper type or the fixed caliper type. A brake pad is arranged on each side of the brake disc, which is only shown by its axis of rotation A ( Fig. 3 To accommodate the brake pads 2, 3, the brake caliper 1 is provided with a pad recess 6, over which a pad retainer 7 extends. The pad retainer 7 bridges the pad recess 6 in such a way that it extends transversely over both brake pads 2, 3, namely the brake pad 2 located on the outside of the vehicle and the brake pad 3 located on the inside of the vehicle, which are designed differently here.

[0033] The brake pads 2, 3 consist according to Fig. 4 Each brake pad consists of the actual friction lining 4 and a backing plate 5. The backing plate 5 is preferably made of cast metal. The backing plate 5 serves to improve the distribution of the brake pressure across the pad surface. It also guides and supports the brake pad either on the brake caliper 1 itself or on an axle-mounted brake carrier.

[0034] The in Fig. 7 The brake pad retainer 7, shown as a separate component, is elongated along its longitudinal centerline L1 and extends for most of its length parallel to the axis A around which the brake disc rotates. Its first end section 7a, shown on the right, i.e., the vehicle-side end of the retainer 7, is directly received in the brake caliper 1, for which purpose the first end section 7a of the retainer 7 is inserted into a slot 14 ( Fig. 3 ) of the brake caliper 1. The other end section 7c of the retainer 7 is indirectly attached to the brake caliper 1 by means of, among other things, a bolt, which will be explained in more detail later.

[0035] To secure the two brake linings 2, 3 in the lining shaft 6, the retainer 7 is designed as a rigid bracket and combined with a flexible leaf spring 9 to form a retaining arrangement 8 ( Fig. 3 The purpose of the two-part retaining arrangement 8 is to fix both brake pads 2, 3 in relation to the pad recess 6 in such a way that the brake pads 2, 3 cannot protrude or fall out of the pad recess 6 radially outwards, with respect to the axis A of the brake disc.

[0036] The hold-down device 7 has a trough-shaped cross-section over the majority of its total length and in particular on its central section 7b, with a base 7d arranged on the longitudinal centerline L1 of the hold-down device 7, to which side flanks 7e, 7f are attached along both longitudinal edges of the base 7d, reinforcing the central section 7b of the hold-down device 7 against bending forces.

[0037] The flat bottom of the groove formed by the base 7d, which has approximately the width of the leaf spring 9, is adjoined on both sides by the side flanks 7e, 7f at an angle between 15° and 90°.

[0038] The retainer 7 rests directly on the upper edge of the backing plate 5 of the inner brake lining 3 at its base 7d. Simultaneously, the flanks 7e, 7f of the retainer can be supported laterally by stops 5a at the upper edge of the backing plate 5. The two stops 5a prevent the retainer 7 from making large lateral movements relative to the inner brake lining 3.

[0039] The leaf spring 9, made of spring steel, also extends along the longitudinal centerline L1. It is secured at one end 9a in a first spring abutment and at the other end 9c in a second spring abutment. Both fixings are removable to allow access to the brake pad retainer 7 for removal of the spring 9 and the pad retainer 7 located beneath it, thus enabling access to the pad recess 6 from the outside for replacing the brake pads 2, 3.

[0040] The leaf spring 9 extends along the outside of the retainer 7 and is supported from the outside against the retainer 7, in particular against its central section 7b in the area of ​​the base 7d (see Fign. 3 , 9 ), which means that it is spring-loaded towards both brake pads 2, 3. Therefore, the retainer 7, although itself rigid, is supported under constant spring force against both brake pads 2, 3 and exerts a force on each of them directed towards the axis of rotation A.

[0041] According to the Figuren 8 und 9 The leaf spring 9 is supported on the outside of the brake pad retainer 7 only by a very short longitudinal section, shaped as a kink or bend 9e. This short longitudinal section, located on the middle third of the leaf spring 9's length and above the brake pad recess 6, features the kink 9e, which extends transversely to the leaf spring's longitudinal axis. Central sections of the leaf spring adjoin the bend 9e on both sides. However, the leaf spring 9 only contacts the central section 7b of the retainer 7 with the bend 9e on its outer surface. Therefore, the retainer 7 is only subjected to the spring force directed towards the brake pads at this point of contact.

[0042] Overall, the leaf spring is according to Fig. 8 characterized by its upper main surface 9.2, its lower main surface 9.1, and, successively along its length, the first spring end 9a, the spring middle section 9b, and finally the second spring end 9c. The leaf spring 9 has a constant width along its entire length, which simplifies its manufacture.

[0043] The outermost ends of the springs 9a and 9c are formed by positive locking elements 10a and 10c, which are angled relative to the main extension of the leaf spring. With respect to the main sides 9.1 and 9.2, the positive locking elements 10a and 10c extend in opposite directions from the main extension of the leaf spring such that the first positive locking element 10a is located on the first main side 9.1, and the second positive locking element 10c is located on the second main side 9.2.

[0044] The leaf spring 9 has on its central section 9b the two kinks or bends 9f, 9e of opposite bending direction, of which the bending outer side of the bend 9f, which is located closest to the first spring end 9a, is on the second main side 9.2, whereas the bending outer side of the other bend 9e is on the first main side 9.1.

[0045] In its assembled state, the bend 9f is located just outside a slot 14 in the brake caliper, i.e., still in front of the slot opening. This is because only a short, straight spring section 9d lies between the bend 9f and the spring end 9a with the positive locking element 10a. Its length is less than one-sixth of the total length of the leaf spring. It is primarily by means of this short spring section 9d that the leaf spring 9 bears against the upper inner surface 14b of the slot 14 in the brake caliper.

[0046] The other, opposite bend 9e, however, is arranged more centrally and is located on the middle third of the length of the leaf spring in its central section 9b.

[0047] A first spring abutment for the leaf spring 9 is located on the inside of the vehicle at the brake caliper 1 in the form of the slot 14, and a second spring abutment is located on the outside of the vehicle next to the pad recess 6. The outer spring abutment has a bolt 13 for securing the respective spring end 9c of the leaf spring 9. The brake caliper 1, on the other hand, is provided with the recess 14, open towards the pad recess 6, to form the inner spring abutment. This recess provides space for both the end of the retainer 7 and the spring end 9a of the leaf spring, namely for a short end section of the leaf spring 9, less than 3 cm long.

[0048] For the assembly of the hold-down arrangement 8, consisting of the hold-down device 7 and the leaf spring 9, it can be advantageous if the ends of these two components, which are inserted together into the slot 14 of the brake caliper 1 in an oblique movement, are locked to each other longitudinally. For this purpose, the hold-down device 7 is provided with a recess 7g at this end ( Fig. 7 and Fig. 11 The downwardly curved positive locking element 10a of the leaf spring 9 engages in the recess 7g in a form-fitting manner, similar to a hook in a matching eyelet. This longitudinal locking of the leaf spring 9 on the retainer 7 means that as soon as the end 7a of the retainer 7 is in the slot 14 of the brake caliper 1, the leaf spring 9 is locked longitudinally, i.e., axially captured on the retainer 7. This is achieved by dimensioning the height of the slot 14 and the length of the positive locking element 10a, which extends transversely to the slot, such that it is not possible to release the positive locking element 10a from the recess 7g of the retainer within the slot 14.

[0049] This measure serves safety and facilitates the subsequent fixing of the retainer 7 and, above all, the leaf spring 9 at its other end, i.e., in the area of ​​the spring abutment shown on the left, located on the outside of the vehicle.

[0050] The slot 14 formed in the brake caliper 1 is open laterally towards the retainer 7, so that the slot 14 is bounded only by a rear wall 14a, an upper inner surface 14b, and a lower inner surface 14c of the brake caliper. The upper inner surface 14b is the wall of the slot 14 facing the axis or axis of rotation A of the disc brake. The lower inner surface 14c is the wall of the slot 14 facing away from the axis or axis of rotation A. Preferably, the two inner surfaces 14b and 14c extend parallel to each other, thus forming a parallel slot.

[0051] The retainer 7 is angled, i.e., inclined, at its end section 7a relative to the central section 7b. After the angled section, the end section 7a of the retainer 7 runs perfectly straight, i.e., without any bend or offset, up to the end face 7m opposite the rear wall 14a. In the assembled state, the center line L1 of the retainer 7 is oriented substantially parallel to the brake disc axis A. Only the end section 7a is inclined or angled by 10° to 35° relative to the center line L1 and thus also to the brake disc axis A, preferably by 15° to 25° and particularly preferably by 20°.

[0052] According to Figur 3a The slot 14 in the brake caliper 1 is also arranged obliquely to the axis A in the direction of its slot depth. The angle W of the oblique position relative to the axis A is essentially equal to the angular deflection of the inclined end section 7a of the retainer 7. The leaf spring 9 is thus supported under spring force against the upper inner surface 14b of the slot 14, which faces the axis A.

[0053] The Figur 3a Figure 1 illustrates the process for producing the slot 14 using a milling tool F. Because of the simple shape of the slot 14 with no side walls, it can be easily produced.

[0054] The disc cutter F, rotating on axis A3, performs a single pass according to the specifications shown in Fig. 3a The double arrow indicates that the upper inner surface 14b, the parallel lower inner surface 14c, and the back wall 14a of the slot are machined. The machining is thus performed by a single forward and subsequent return movement of the disc cutter F. These movements occur at an angle W and perpendicular to the cutter axis A3.

[0055] The width of the cutter disc F determines the height of the slot 14 created. The direction of the cutter disc F's feed results in the resulting back wall 14a of the slot not being flat, but having the shape of a circular arc whose center lies outside the slot 14. In the Figur 7 and the Figur 11 This circular arc 27 is illustrated, however here by means of the corresponding circular contour of the front face 7m of the retainer 7. The imaginary center of the circular arc 27 is located outside the brake caliper, namely outside above the lining channel 6.

[0056] Alternatively, the disc cutter F, after being inserted to its maximum depth in the direction of slot 14, can be moved slightly laterally and then withdrawn. This forms a back wall 14a, which consists of a straight central section and smoothly adjoining circular arc segments, the centers of which are located outside the brake caliper above the pad recess 6.

[0057] By inclined the upper inner surface 14b of the slot 14 at the angle W, advantages arise for the strength of the brake caliper 1. Because the material thickness M ( Fig. 3 The clearance between the upper inner surface 14b and the outer surface of the brake caliper 1 increases significantly from the pad recess 6, forming a widening wedge. This also saves valuable space at this important point on the brake caliper 1. This is advantageous because there is only a small radial clearance between the outer surface of the brake caliper and the vehicle wheel or rim rotating around the caliper. Especially in the area around the pad recess, there is usually very limited space for attaching the retainer 7 or the assembly consisting of the retainer 7 and the leaf spring 9.

[0058] The recess 7g of the hold-down device 7 is open towards the rear wall 14a, the upper inner surface 14b, and the lower inner surface 14c of the slot 14, but is bounded laterally, i.e., towards the lateral openings of the slot 14, by side sections 7k of the first end section 7a of the hold-down device 7. The side sections 7k also run inclined towards the central section 7b, as they are part of the first end section 7a, which is inclined overall towards the central section 7b. The recess 7g is therefore U-shaped, open at the top and bottom, with the end opening of the U-shaped recess 7g pointing towards the rear wall 14a of the slot 14.

[0059] According to Fig. 7 The hold-down device 7 is narrower on its second end section 7c, located on the outside of the vehicle, with a width B, than on the comparatively longer longitudinal section or central section 7b, which has the shape of a channel. The width B on this end section 7c is no greater than the width of the base 7d. Most importantly, the hold-down device 7 on this end section is provided with a bend 11 adjoining the elongated base 7d, in that the hold-down device 7, starting from the base 7d, first has a downward bend 11a, and then a second bend 11b as a counter-bend. A straight longitudinal section 12 immediately adjoins the second bend 11b as the outer end of the hold-down device 7. The straight longitudinal section 12 is thus located lower, or closer to the axis of rotation A, than the base 7c of the channel-shaped central section 7b.

[0060] Preferably, the S-shaped bend 11 is designed such that its second bend 11b, which transitions directly into the straight end section 12, does not connect directly to the first bend 11a, but rather a short, straight section 11c is located between them. Its angle to the trough-shaped longitudinal section is, for example, 110°.

[0061] The longitudinal section 12 extends over a length L essentially parallel to the axis of rotation A and parallel to, and offset from, the significantly longer, trough-shaped central section 7b. For example, the hold-down device 7 can have a total length of approximately 150 mm. In this case, the end section 12 is offset by 15 to 20 mm from the base 7d of the trough-shaped section. The area of ​​the offset 11 can be reinforced by one or more stiffening beads 11d, since the hold-down device 7 is relatively slender here with a width B, and bending forces can occur. Preferably, the hold-down device 7 consists of stamped and formed sheet steel with a material thickness of at least 4 mm.

[0062] With the bolt 13 mounted on the brake caliper, it is engaged without contact by the offset 11 or the longitudinal section 12 forming the end of the second end section 7c of the retainer 7 ( Fig. 4 Nevertheless, this end section of the retainer is secured by the bolt 13 positioned above it in such a way that it cannot detach from the covering channel 6 under any circumstances. The offset 11, or the longitudinal section 12, as the end of the second end section 7c of the retainer 7, has such a vertical distance from the bolt 13 in the assembled state that no contact occurs.

[0063] The retainer 7 rests on the backing plates 5 of both brake pads 2, 3 from above and is initially only movable in its longitudinal direction, while being held fixed transversely by means of lateral shaped elements of the brake pads. Both brake pads 2, 3 are freely movable in the pad recess 6 in the direction of the axis of rotation A of the brake disc and are guided with a certain amount of play in the circumferential direction of the brake disc. This combination of freedom of movement results in the retainer 7 being freely movable longitudinally on the brake pads 3 and having limited transverse movement, i.e., floating, with the brake pads 3. In the installed state, its longitudinal movement is tightly limited by respective stops on the brake caliper 1. For this purpose, the stop surfaces between which the retainer 7 can move are mechanically machined, e.g., by milling the brake caliper 1.

[0064] In the longitudinal direction of the retainer 7, a projection 15, formed on the brake caliper 1, is located a short distance from its second end section 7c. The projection 15 therefore forms a stop that limits the longitudinal movement of the retainer 7 outwards towards the vehicle. Preferably, the projection 15 extends almost to the circumference of the bolt 13, but without touching the bolt 13.

[0065] Two bearing blocks 50, integrally formed on the brake caliper 1, each have a bore in which the bolt 13 sits on the axle 13a. To prevent the bolt 13 from loosening in the longitudinal direction from the bearing blocks 50 and thus from the caliper 1, suitable retaining rings, cotter pins, or the like are provided on the bolt 13.

[0066] The Fign. 1 , 3Figure 1 shows details of how the outer spring end 9c of the leaf spring 9 is fixed to the abutment. Besides the bolt 13, this spring abutment includes a mounting bracket 60, which is pivotally connected to the brake caliper 1 about the bolt axis 13a by means of the bolt 13. The leaf spring 9 rests against the inner or underside of the bracket 60, which faces the axis 13a, with its spring end 9c. The leaf spring is provided with the upwardly extending positive locking element 10c at this spring end 9c. The positive locking element 10c engages in a slot-shaped opening 61 in the bracket 60, thus securing the pivot position of the bracket 60.

[0067] The in Fig. 10 The bracket 60, shown as a separate component, is the vehicle-outer abutment element for the leaf spring 9. The bracket 60 consists of a central section 62 parallel to the axis 13a, on which the opening 61 can be located, and two side sections 63 arranged approximately at right angles to the central section 62. Fig. 10 These side sections are designed as tabs 63 and each has a round opening 66 arranged on the axis 13a. Since the two openings 66 are aligned with each other on the axis 13a, the axis 13a is simultaneously the axis of alignment for the two openings 66. The bolt 13 passes through both openings simultaneously.

[0068] The edge of the tabs 63 facing the disc brake pivot axis A has an edge contour 64 that is curved towards the axis 13a. The contour section of the contour 64 facing the disc brake axis A forms a stop, since the contour profile is such that the contour 64 has a greater distance A1 in some sections and a smaller distance A2 from the axis 13a in others. For example, the contour 64 can be eccentric or it can be arc-shaped, but then with an offset from the axis 13a.

[0069] The bolt 13 is the fastening element used to detachably attach the bracket 60, which serves as both a support and a locking element, to the brake caliper 1. Simultaneously, the end 9c of the leaf spring 9 rests under spring tension against the inner surface of the central section 62 facing the bolt 13. This inner surface therefore forms the support 62a against which the spring end 9c rests. The sum of these measures ensures and maintains the bending stress in the leaf spring 9.

[0070] An additional safety measure is the positive engagement of the upwardly angled positive locking element 10c formed at the outermost end 9a of the spring into the opening 61 of the bracket 60.

[0071] The assembly of the device, consisting of brake pad retainer 7, leaf spring 9, bolt 13, and bracket 60 as a support and locking element, is carried out by first placing one end 9a of the leaf spring 9 onto the retainer 7 so that it engages positively in the recess 7g of the vehicle-internal end section 7a of the retainer 7. The retainer and leaf spring, thus provisionally connected, are then pushed into the slot 14 in an oblique motion. The first end section 7a, which is angled relative to the central section 7b, is then at least partially located within the slot 14, which is inclined towards the brake disc axis A, together with the leaf spring 9. The retainer 7 is then pivoted downwards at its other end until this other end reaches the retaining surface 43. At the same time, the retainer rests itself from above onto the backing plate 5 of the vehicle-internal brake pad 3 between the two stops 5a.

[0072] In the next step, the bracket 60 is placed onto the other end 9c of the spring. This is facilitated by the engagement of the positive locking element in the opening 61 of the bracket 60, thus making it even safer for the installer. The end 9c of the spring 9 is supported against the abutment 62a on the inside of the bracket 60. Now, only the bracket 60 is moved downwards by manual pressure and by bending the leaf spring until the bolt 13 passes along the axis 13a into the bearing blocks 50 and simultaneously through the openings 66 of the bracket 60. The pressure on the bracket 60 can then be released, as the tension force of the leaf spring 9 is securely absorbed by the bracket 60, which forms the abutment element, in conjunction with the bolt 13.

[0073] The leaf spring 9, with its spring preload, holds the retainer 7 on the brake pads 2, 3, ensuring that in the event of a strong impact, e.g., when driving over a pothole, the brake pad, which lifts outwards, is pressed back into its original position. Should the leaf spring 9 break, e.g., due to mechanical forces, and thus lose its holding function, the retainer 7 is still held in place by the bracket 60 above it and by the slot 14, preventing the brake pads from coming loose.

[0074] The in Fig. 7 The depicted offset 11 of the narrower second end section 7c of the retainer 7, located on the outer side of the brake disc, has the advantage that disc brake components protrude less radially outwards in this area, thus helping to alleviate the tight space between the disc and the surrounding vehicle wheel, which rotates around the brake. However, the offset 11 results in a space requirement in the area of ​​the brake pad 2, which is located on the outer side of the brake disc. Therefore, the brake pad is designed in a special way, which will be explained in more detail below.

[0075] According to Fig. 6 The brake pad 2, located on the outer side of the brake disc, consists of the friction lining 4, which is designed to bear against the brake disc, and the stable backing plate 5. The latter is made, for example, of cast steel, with the front surface serving as a mounting surface 16 for the friction lining 4, while the rear surface 17 serves as a pressure surface for transmitting the brake pressure. This rear surface 17 of the backing plate 5 rests against a corresponding pressure-exerting surface 18 of the brake caliper 1. The surface 18 also forms a wall of the pad recess 6.

[0076] The circumferential contour of the back plate 5 is determined by an upper or, with respect to the axis of rotation A, outer edge 21, an inner or lower edge 22 facing the axis of rotation A and two side edges 23a, 23b extending between the upper and the lower edge, which run parallel to each other.

[0077] The upper or outer edge 21 is characterized by a main profile that follows the shape of the brake disc. For this purpose, the upper edge 21 exhibits a predominantly arc-shaped profile, i.e., along its majority of its length, which adopts the circular shape of the circumference of the round brake disc. This has the advantage that the brake pad 2 does not protrude radially outwards beyond the technically required circumference of the brake disc.

[0078] The backplate 5 is supported circumferentially by the two side edges 23a, 23b, so that the braking torques are transmitted to the brake caliper 1 or, alternatively, to an axle-mounted brake carrier of the disc brake. To a lesser extent, the transmission of the braking torques can also occur via the lower edge 22 of the backplate 5 to the brake carrier, if a brake carrier is present.

[0079] The friction lining 4 also features a main contour at its upper or outer edge 31, which follows the shape of the brake disc. For this purpose, the upper edge 31 exhibits a predominantly arc-shaped contour, i.e., over its majority of its length, which adopts the circular shape of the circumference of the round brake disc. As a result, this edge does not protrude radially outwards beyond the circumference of the brake disc, while simultaneously providing a maximum contact area between the friction lining 4 and the brake disc.

[0080] If the edges 21, 31 have a generally curved shape, this includes individual deviations from this main design. For example, a narrow recess 33 can be arranged off-center in the friction lining 4 and backing plate 5, which serves for the attachment of an electrical brake pad wear sensor. Furthermore, individual small projections can be formed on the edge 21 without affecting the curved main design of the edge; these can be advantageous, for example, during the production of the brake pad.

[0081] To create space and clearance for the offset 11 of the hold-down 7, the main course of the upper edge 21 of the back plate 5 is interrupted exactly in the middle between the two side edges 23a, 23b by a partial reduction 25 of the edge 21. The reduction 25 is wider than the width B of the offset hold-down section.

[0082] Only in the area of ​​this reduction 25 is the height of the back plate 5 therefore reduced radially to such an extent, with respect to the distance to the axis of rotation A, that a free space is created in the back plate 5 through which the hold-down device 7 extends with at least a part of its cross-section.

[0083] To create space for the hold-down device 7, the friction lining 4 also has a clearance in the same area. While the friction lining 4 is otherwise mainly curved along its outer edge 31, this primary shape is interrupted in the middle between the two side edges 23a, 23b by a depression 35 in the upper edge 31. The depression 35 also creates a clearance along the circumferential contour of the friction lining 4, through which the hold-down device 7 can extend with at least part of its cross-section. For this purpose, the depression 35 is wider than the width B of the offset hold-down device section.

[0084] The bottom of the recess 25 in the back plate 5 is deeper and thus located closer to the axis of rotation A than those sections 31a, 31b of the upper edge 31 of the friction lining 4 which directly adjoin the recess 35 formed in the friction lining 4 in the circumferential direction.

[0085] The reduction 25 therefore creates a clearance for the retainer to pass over it. As a result, the retainer 7 occupies a position less radially outward along this part of its length, which reduces the risk of brake components rubbing against the inner wheel of the vehicle, a risk caused by the limited space between the disc brake components and the vehicle wheel rotating around the brake.

[0086] According to Fig. 6 A projection 40 is integrally formed on the rear side 17 of the backplate 5, below its upper edge 21. The projection 40 is positioned closer to the upper edge 21 than to the lower edge 22 of the backplate 5. It is positioned centrally in the circumferential direction of the brake pad 2, thus having the same distance to both side edges 23a, 23b. For support on a correspondingly shaped surface of the brake caliper 1, it has at least one downwardly directed support surface 42 ( Fig. 4 ) provided. This is positioned at right angles to the rear side 17 of the back plate 5 and rests on the bottom of a recess 38 ( Fig. 5b ) off, with which the brake caliper 1 is equipped.

[0087] In a top view, the projection 40 has a rectangular plan. The two outer corners 41 of the projection 40, spaced apart from the rear 17, are each rounded, with a corner radius R of at least 4 mm. The rounding of the corners 41 offers manufacturing advantages with regard to the machining of the corresponding recess 38 in the brake caliper 1 ( Fig. 5b ). This recess 38 serves as a pad receptacle by receiving at least part of the projection 40 of the brake pad, and for this purpose it is provided with correspondingly rounded inner corners 39 with a corner radius of at least 4 mm.

[0088] Facing away from the support surface 42, a flat retaining surface 43 with a width of 10 to 20 mm and a length or depth of at least 7 mm is formed on the projection 40. The retaining surface 43 is lower and thus located closer to the axis of rotation A than the recess 25. The retainer 7 rests against the brake lining exclusively on the retaining surface 43, namely with the underside of the short longitudinal section 12 following the offset 11, which forms a bearing surface 12a.

[0089] The longitudinal section 12 is also the end section of the second end section 7c and thus of the hold-down device 7. Its end face is opposite a transverse wall of that recess 38 of the brake caliper 1 which at least partially accommodates the projection 40.

[0090] The hold-down surface 43 for the installation of the hold-down device 7 is adjoined by a comparatively shorter transition surface 44 towards the friction lining 4. The transition surface 44 rises to the bottom of the recess 25, for example in the form of a bend or alternatively a sloping ramp. The transition surface 44 meets the bottom of the recess 25 at an edge 45, whereby according to Fig. 4 this edge 45 is arranged in a plane of the back plate 5 which is located between the plane of the mounting surface 16 and the plane of the back 17.

[0091] Adjoining the retaining surface 43 laterally, i.e., in the circumferential direction of the brake pad, is an edge region 47 which projects beyond the retaining surface 43. The end section 12 of the second end section 7c of the retainer 7, which is supported on the retaining surface 43, is therefore flanked by the two raised edge regions 47, so that the retainer 7 has little or no lateral play with respect to the brake pad 2.

[0092] With the bracket 60 mounted, it not only serves as a support element for the leaf spring 9, but also as a locking element. The edge contours 64 of the tabs 63 form a stop that is not, or only slightly, spaced from the opposing surfaces formed on the projection 40. This results in the brake pad 2 with its support surface 42 being unable to lift off the brake caliper, or only to a very limited extent. This locking effect is achieved by a groove 48 forming in each of the two edge regions 47 of the projection 40, which acts as a counter-stop.

[0093] Viewed in the circumferential direction of the brake pad 3, the grooves 48 are arranged in front of and behind the center of the back plate 5, with their distance to this center being the same. Each groove 48 extends along the respective side surface 49 of the projection 40. The bottom of each groove 48 faces the bolt 13 and is either at a small distance from the respective contour 64 of the bracket 60, or there is even permanent contact between the contour 64 and the bottom of the groove 48. If there is no permanent contact, the distance is in any case small and, above all, smaller than the distance of the bolt 13 to the offset 11 or to the end section 12 of the retainer 7.

[0094] The contours 64 on the bracket 60, which serves as a locking element, each form a stop, and the grooves 48 on the brake pad 2 each form the counter-stop. Therefore, should the brake pad 2 strike upwards due to strong vibrations, which would cause the retainer 7 to lift by the same amount, this movement is blocked at the latest when the groove 48 abuts the contour 64. Any further movement, which would then have to be absorbed entirely by the leaf spring 9, is prevented, thus extending the service life of the leaf spring 9.

[0095] The grooves 48 can be open along one side, namely towards the respective side surface 49 of the projection 40. The grooves 48 can be open at their end facing away from the back plate 5. On the side facing the back plate 5, they are of such length that they extend not only over the depth of the projection 40, but also into the thickness of the back plate 5. This allows the stop formed by the contour 64 of the side sections 63 to be located close to the back plate 5. This minimizes or even prevents a tilting moment in the event of contact with the brake pad 3.

[0096] On the inside of the vehicle, the retainer 7 is only slightly spaced from the leaf spring 9; in some places, one end 9a of the leaf spring 9 even engages positively in the U-shaped recess 7g of the first end section 7a of the retainer 7. The engagement of the leaf spring 7 in the recess 7g is similar to that of a hook engaging in an abutment.

[0097] The leaf spring 9 is supported by the spring segment 9d, which adjoins the hook-like spring end 9a, on the upper inner surface 14b of the slot 14, which faces away from the pad recess 6. Thus, the inner of the two brake pads can only lift slightly from its radial support surface due to the action of the retainer 7.

[0098] Overall, it is achieved that the two pads 2, 3 are held radially to the disc brake axis A by means of spring force, and that in the event of one or both brake pads lifting off, the corresponding distance is narrowly limited by stops and counter-stops.

[0099] According to the Figuren 7 and 9The hold-down device 7 is provided at its first end section 7a with two side sections 7k extending from the base 7d of the hold-down device 7 at an angle to each side of the recess 7g also located in the first end section 7a. The side sections 7k are extensions of the side flanks 7e, 7f of the central section 7b, which is designed as a channel, and, viewed in the longitudinal direction of the hold-down device 7, have an angled but internally straight course compared to the central section 7b. The remaining part of the first end section 7a is also angled relative to the central section 7b.

[0100] To ensure a tight fit against the opposite, arc-shaped rear wall 14a of the slot 14, the outermost end of the retainer 7 is formed by the front face 7m, which extends along a corresponding arc 27 ( Fig. 7 ). The imaginary center of the circular arc 27 is located outside the hold-down 7, namely above the central section 7b.

[0101] The Figuren 11 und 12 Figure 1 shows another embodiment of the hold-down device 7. With regard to its stability, it can be advantageous if the two side flanks 7e, 7f are additionally extended by extending not only along the long, straight base 7d, but also along the first end section 7a, which is arranged at an angle to it.

[0102] The additional side flank sections can serve to support the retainer 7, which is located in the slot 14 of the brake caliper, laterally against the brake caliper 1, provided that the inner width between the additional side flank sections is equal to or greater than the width of the slot 14.

[0103] The side flanks 7e, 7f are angled more steeply with respect to the base 7d than in the first embodiment of the hold-down device. Furthermore, Fig. 11 It can be observed that the height of the side flanks 7e, 7f decreases towards the second end section 7c. This is because, in practice, there is only a small gap to the surrounding vehicle wheel, i.e., to the inside of the wheel rim, in this part of the disc brake that is located further outwards from the vehicle. Reference symbol list

[0104] 1 Brake caliper 2 Brake pad 3 Brake pad 4 Friction pad 5 Backing plate 5a Stop 6 Pad recess 7 Retainer 7a First end section 7b Middle section 7c Second end section 7d Base 7e Side flank 7f Side flank 7g Recess 7k Side section 7m Front face 8 Retainer assembly 9 Leaf spring 9a End of leaf spring 9b Middle section 9c End of leaf spring 9d Spring section 9e Bend, kink 9f Bend,10a Bend 10c Form-locking element 11 Offset 11a Bend 11b Bend 11c Straight section 11d Stiffening bead 12 Longitudinal section 12a Bearing surface 13 Bolt 13a Axis 14 Slot 14a Back wall 14 Upper inner surface 14c Lower inner surface 15 Projection 16 Mounting surface 17 Back 18 Surface 21 Upper edge 22 Lower edge 23a Side edge 23b Side edge 25 Recess in the back plate 27 Circular arc 31 Upper edge 31a Section 31b Section 33 Recess 35 Recess in the friction lining 38 Recess in the brake caliper 39 Inner corner 40 Attachment 41 Corner 42 Support surface 43 Retaining surface 44 Transition surface 45 Edge 47 Edge area 48 Gutter 49 Side 50 Bearing block 60 Bracket, abutment element, locking element 61 Opening 62 Middle section 62a Abutment 63 Side section, tab 64 Contour, stop 66 Opening A-axis, axis of rotation of the brake disc A1-distance A2-distance A3-axis of rotation of disc cutter B-width F-disc cutter L-length of the end section L1-longitudinal centerline M-material thickness R-radius W-angle

Claims

1. Leaf spring (9) of a retainer arrangement for the brake linings of a vehicle disc brake, with two main sides (9.1, 9.2) and successively a first spring end (9a), a spring middle section (9b) and a second spring end (9c), characterized by the fact thatat the termination of the spring ends (9a, 9c) each form positive locking elements (10a, 10c) which extend in opposite directions from the main sides (9.1, 9.2) such that the first positive locking element (10a) is located on the first main side (9.1), and the second positive locking element (10c) is located on the second main side (9.2), and wherein the leaf spring has at least two bends (9f, 9e) of opposite bending direction on the spring middle section (9b), of which the bend outer side of the bend (9f) located closest to the first spring end (9a) is located on the second main side (9.2), and the bend outer side of the at least one further bend (9e) is located on the first main side (9.1).

2. Leaf spring according to claim 1, characterized by the fact that the bend (9f) located closest to the first end of the spring (9a) is located on the first sixth of the total length of the leaf spring (9).

3. Leaf spring according to claim 1 or 2, characterized by the fact that the bend (9f) located closest to the first spring end (9a) is arranged at a distance of 1.5 cm to 3 cm from the first positive locking element (10a).

4. Leaf spring according to one of claims 1 - 3, characterized by the fact that the further bend (9e) is arranged on the middle third of the total length of the leaf spring (9).

5. Leaf spring according to one of claims 1 - 4, characterized by the fact that the width of the main sides (9.1, 9.2) is constant over the entire length of the leaf spring (9).